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Feb 14, 1956 B. F. TRACY ADJUSTABLE DIAMETER ROTARY CUTTING HEAD FORMINING MACHINES 2 Sheets-Sheet 1 Filed NOV. 13, 1955 fleg 'am z'rz 1 17204 INVENTOR ATTORNEYS.

Feb. 14, 1956 B. F. TRACY 4,

ADJUSTABLE DIAMETER ROTARY CUTTING HEAD FOR MINING MACHINES Flled Nov13, 1953 2 Sheets-Sheet 2 M MMN WM RN v jazz am inliTnac y INVHN'I'ORATTORNEYS.

United States PatentfO ADJUSTABLE DIAMETER ROTARY CUTTING HEAD FORNHNING MACHINES Benjamin F. Tracy, Point Pleasant, W. Va., assignor toGoodman Manufacturing Company, Chicago, ,Ill., a corporation of IllinoisApplication November 13, 1953, Serial No. 391,789

8 Claims. (Cl. 262-7) This invention relates generally to boring typemining machines and particularly to an improved adjustable diameterboring head. I v

By the present invention, the boring head comprises a rotatable hubhaving a rod or pair of rods mounted transversely across it and havingdiametrically opposed cutter bit clusters at least on the extreme outerends. The cutter bit means are eccentrically disposed, on long and shortarms, so the cutter bits are non-tracking and, therefore, cut separateconcentric kerfs.

An important object of the present invention is to provide a structurefor adjustably varying the boring diameter of the head by shifting therod means lengthwise of itself to change the eccentricity of the cutterbit means relative to the hub without changing the spacingbetween thecutter bits and without changing the length of the rod means itself.Thus, the machine may be adapted to mine seams of varying thickness.

With the foregoing and other objects in view which will appear as thedescription proceeds, the invention consists of certain novel details ofconstruction and combinations of parts hereinafter more fully describedand pointed out in the claims, it being understood that changes may bemade in the construction and arrangement of parts.with out departingfrom the spirit of the invention as claimed.

Referring to the drawings:

, Figure l is an elevational view illustrating mining machine headsconstructed in accordance with the invention.

Fig. 2 is a view illustrating the operation of the breaker roller andbreaker cone forming a part of the cutting head.

Fig. 3 is a sectional view illustrating the. operation of the breakingcone formed integral with the pilot anger of the head. a v

Fig. 4 is an elevational view ilustrating the cutting head as it appearsin operation.

Fig. 5 is an end elevational view illustrating bits as supported by thetool holders.

Referring to the drawings in detail, as illustrated by Fig. 1 of thedrawings, a supporting bar 5 is shown representing a supporting beamforming a part of a mining machine, not shown, the supporting barproviding a support for the cutting heads 6 and 7. I

While two of these cutting heads are shown, forming a part of the miningmachine, in the instant case, it is to be understood that it is withinthe scope of the invention to use a single cutting head in a miningmachine, or as many cutting heads as required, without departing fromthe spirit .of. the invention.-- Since these cutting heads are identicalin construction, a single cutting head will be described in detail. Thecutting head comprises a block or hub 8 which is formed with spacedlongitudinally disposed bores 9 in which the rods 10 slide, the rodsbeing of lengths to extend substantial distances beyond the ends of theblock or hub 8, as better shown by Fig. 1 of the drawings.

Secured on the outer ends of the rods 10 are cutter arm extensions 11and 111. Extension 11 is a one-piece construction serving the triplefunctions of: bridging or connecting the rods; forming a stop to limitshifting of the rods in one direction; and providing support for toolholder 11a. Extension 111 serves the same three functions but comprisesa two-part construction including a bridging section 50 andatool-holdingsection 51 for tool holder 11b. Both tool holders 11a and11b support bits 12 in the conventional manner, these bits beingarranged in circular arcs to match the arcs of the kerfs cut thereby.Sections 51 are formed with lugs 9' that fit in notches 10' of sections50, there being provided apertured lugs 12' and 13' on these twosections and through which bolts 14 extend, removably securing thecutterarm end portion 51. Due to this construction, it will be seen that thecutter arm portions 51 may be replaced by longer or shorter counterpartsto increase or decrease the maximum diameter of the cut.

The section 50 serves as a spacer, placing the tool holder 11b radiallyoutward with respect to holder 11a so that their cutter bits cutnon-tracking concentric kerfs 52 and 53 respectively in the mine face.

The block or hub 8 also supports the tool holder 14 in which the bits 15are secured, the tool holder 14 being formed with its outer edge or theedge in which the bits 15 are mounted, in the arc of a circle, so thatin operation the bits 15 will cut a circular kerf 54 concentric withkerfs 52 and 53.

The reference character 16 indicates the pilot auger which is secured tothe forward side of the block or hub 8. The pilot auger extendsforwardly beyond the bits 12 and 15, whereby the bits are centered andheld against lateral movement while in operation.

At the inner end of the pilot auger is the breaking cone 17 which fitsinto the bore formed by the pilot auger 16, and contacts with the outeredges of the bore to we'dge the material being mined laterally from thebore into the clearance provided by the kerf 54. Secured to the cutterarm extension 11 at one end of the cutting head, is a breaking roller 18which is arranged on the side of the cutter arm extension 11, thebreaking roller 18 being disposed at an oblique angle with respect tothe side of the cutter arm extension 11 on which it is mounted, so thatit will track inthe kerf 53 and break the outer core 56 into theclearance provided by kerf 52.

A breaker cone'19 is mounted in a bracket 20 secured on one side edge ofthe block or hub 8, and is adapted to track within the kerf or cut 54formed by the bits 15 and dislodge the core 57 into the clearanceprovided by kerf 53.

It will be understood that it is within the scope of the invention touse a breaker cone such as shown at 19, in lieu of the breaker rollers18, or vice verse if desired.

Power is applied to the cutter head by means of the shaft 21 which formsa part of the mining machine, not shown, and is'operated in the usualmanner.

It might be further stated that since the rods 10 are mounted forsliding movement within the bores of the block or hub 8, the diametersof the kerfs cut by the bits 12 may be varied to meet variousrequirements of use. In order to hold thecutter arm extensions in theiradjusted positions, andprevent sliding movement of the rods 16 after theadjustment hasbeehmadegthe'wedge'block 22 is drivenbetween one e'nd orthe block or hub 8, and the cutter arm extensions 11 associatedtherewith.

Extending from the edges of the cutter arm extensions 11 are the shovelsor sweeps 23, which contact the dislodged material mined and convey thematerial to the conventional conveying system, not shown.

In operation it is obvious that the cutting head is advanced into thewall of material being mined, with the result that the pilot auger 16will maintain the heads centered, while the bits 12 and 15 cut circularkerfs, the material between the kerfs being spread laterally or brokenaway from the mass, where it may be readily conveyed to a place ofdeposit.

Just by way of a specific example of the utility of the presentinvention, assume that the machine is used in mining a seam of coalwhich varies between 5 /2 and 6 feet in thickness. When in 5 /2-ft.coal, the head would be adjusted as shown in the drawings, with block orwedge 22 being three inches thick. When the machine reaches an areawhere the coal is the full 6 feet high, the boring arms can be adjustedfor the new height simply by removing the wedge and driving it betweenthe hub and the stop 50.

In making the change from 5 /2 foot to 6 foot coal in accordance withthe example above, the core 56 would be thickened to six inches and thecore 57 would be thinned by a like amount. There is a practical limit tohow much these cores can be thickened and have the miner performsatisfactorily; just where this limit is must be determined for eachmine depending on the type of coal or other mineral being worked.

Having thus described the invention, what is claimed is:

1. In a mining machine, a rotary cutter head comprising a hub, a powershaft to which said hub is secured, said hub having bore means extendingtherethrough in a direction transverse to the rotational axis of thehub, supporting rods slidably mounted within said bores, forwardlyprojecting cutting tools mounted on both ends of said rods, means foradjusting said rods, and means for securing the rods in their adjustedpositions varying the diameters of the cuts formed by said cuttingtools.

2. In a mining machine, a rotary cutting head comprising a hub, a powershaft to which said cutting head is secured for rotating said cuttinghead, said hub having bore means extending therethrough in a directiontransverse to the rotational axis of the hub, tool Supporting rodsslidable through said bores, said rods being substantially longer thanthe lengths of said bores, forwardly projecting cutting tools secured toboth ends of said rods, adjustable by adjusting the rods in the boresand securing the rods in adjusted position thereby regulating thecutting range of said cutting tools, means for securing the cuttingtools in their positions of adjustment, and a power auger extendingthrough the hub to guide said cutting tools to their work.

3. An adjustable diameter, multiple-kerf-cutting boring head comprisinga rotatable hub having a cutter-bit-carrying shaft mounted transverselyacross it and having forwardly extending cutters at the extreme oppositeouter ends thereof, said shaft being disposed to provide long and shortarms for said cutters to place the latter in non-tracking relationshipto cut concentric kerfs in a mine face, said shaft being shiftablelengthwise to vary the ratios between the long and short arms, and meansfor selectively locking said shaft in one of at least two shiftedpositions to vary the effective boring diameter of the head withoutchanging the diametrical spacing between the cutters.

4. An adjustable diameter multiple-kerf-cutting boring head comprising arotatable hub having rod means transversely mounted thereacross, havingforwardly extending cutter bit means on opposite ends thereof, and beingtransversely shiftable along its own axis, said rod means being disposedto provide long and short arms for said cutter bit means to place thelatter in non-tracking relationship to cut at least two concentrickerfs, stop means acting between said hub and each end of said rod meansto limit 4 movement of the latter relative to the hub in bothdirections, and locking means acting between said rod means and hub andbeing selective to hold said hub in a position of engagement with eitherof said stop means for varying the effective boring diameter of the headwithout changing the diametrical spacing between the cutter bit means.

5. An adjustable diameter, multiple-kerf-cutting boring head comprisinga rotatable hub having bore means extending therethrough in a directiontransverse to the retational axis of the hub, rod means slidably engagedwithin said bore means and having forwardly extending cutter bit meanson opposite ends thereof, said rod means being disposed with a long armand a short arm thereby placing said cutter bit means in non-trackingrelation to cut at least two annular kerfs concentric with said axis,stop means acting between said hub and each end of said rod means tolimit movement of the latter relative to the hub in both directions, andlocking means acting between said rod means and hub and being selectiveto hold said hub in a position of engagement with either of said stopmeans for varying the effective boring diameter of the head withoutchanging the diametrical spacing between the cutter bit means.

6. An adjustable diameter, multiple-kerf-cutting boring head comprisinga rotatable hub having bore means extending therethrough in a directiontransverse to the rotational axis of the hub, rod means slidably engagedwithin said bore means and having forwardly extending cutter bit meanson opposite ends thereof, stop means acting between said hub and eachend of said rod means to limit movement of the latter relative to thehub in both directions, and locking means acting between said rod meansand hub and being selective to hold said hub in a position of engagementwith either of said stop means for varying the effective boring diameterof the head without changng the diametrical spacing between the cutterbit means.

7. An adjustable diameter, multiple-kerf-cutting boring head comprisinga rotatable hub having a pilot bit extending forwardly therefrom, saidhub having a pair of bores extending therethrough transverselystraddling the rotational axis of the hub, a pair of rods slidablyengaged within said bores, cutter bit means on opposite ends of saidpair of rods, stop means carried at each end of each pair of rods, saidstop means being spaced apart greater than the width of the hub andalternately engageable with the hub to vary the operating radii of saidcutter bit means, and locking means acting between said hub and saidrods for fixing the position of the cutter bit means at operating radiidetermined by said stop means.

8. The combination of claim 7 in which the locking means includes awedge driven between the hub and at least one of said stop means.

References Cited in the file of this patent UNITED STATES PATENTS241,483 Faught May 17, 1881 1,335,723 Campbell Apr. 6, 1920 1,603,621McKinlay Oct. 19, 1926 2,325,294 Woytych July 27, 1943 2,670,190Cartlidge Feb. 23, 1954 2,680,034 Robbins June 1, 1954 FOREIGN PATENTS981,860 France Jan. 17, 1951

